/**
* Copyright (C) 2010-2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include
#include "mongo/db/repl/optime.h"
#include "mongo/stdx/mutex.h"
namespace mongo {
class BalancerConfiguration;
class CatalogCache;
class ShardingCatalogClient;
class ShardingCatalogManager;
class ClusterCursorManager;
class OperationContext;
class ServiceContext;
class ShardRegistry;
namespace executor {
class NetworkInterface;
class TaskExecutorPool;
} // namespace executor
/**
* Holds the global sharding context. Single instance exists for a running server. Exists on
* both MongoD and MongoS.
*/
class Grid {
public:
Grid();
~Grid();
/**
* Retrieves the instance of Grid associated with the current service/operation context.
*/
static Grid* get(ServiceContext* serviceContext);
static Grid* get(OperationContext* operationContext);
/**
* Called at startup time so the global sharding services can be set. This method must be called
* once and once only for the lifetime of the service.
*
* NOTE: Unit-tests are allowed to call it more than once, provided they reset the object's
* state using clearForUnitTests.
*/
void init(std::unique_ptr catalogClient,
std::unique_ptr catalogManager,
std::unique_ptr catalogCache,
std::unique_ptr shardRegistry,
std::unique_ptr cursorManager,
std::unique_ptr balancerConfig,
std::unique_ptr executorPool,
executor::NetworkInterface* network);
/**
* Deprecated. This is only used on mongos, and once addShard is solely handled by the configs,
* it can be deleted.
* @return true if shards and config servers are allowed to use 'localhost' in address
*/
bool allowLocalHost() const;
/**
* Deprecated. This is only used on mongos, and once addShard is solely handled by the configs,
* it can be deleted.
* @param whether to allow shards and config servers to use 'localhost' in address
*/
void setAllowLocalHost(bool allow);
/**
* Returns a pointer to a ShardingCatalogClient to use for accessing catalog data stored on the
* config servers.
*/
ShardingCatalogClient* catalogClient(OperationContext* txn) {
return _catalogClient.get();
}
/**
* Returns a pointer to a ShardingCatalogManager to use for manipulating catalog data stored on
* the config servers.
*/
ShardingCatalogManager* catalogManager() {
return _catalogManager.get();
}
CatalogCache* catalogCache() const {
return _catalogCache.get();
}
ShardRegistry* shardRegistry() const {
return _shardRegistry.get();
}
ClusterCursorManager* getCursorManager() const {
return _cursorManager.get();
}
executor::TaskExecutorPool* getExecutorPool() {
return _executorPool.get();
}
executor::NetworkInterface* getNetwork() {
return _network;
}
BalancerConfiguration* getBalancerConfiguration() const {
return _balancerConfig.get();
}
/**
* Returns the the last optime that a shard or config server has reported as the current
* committed optime on the config server.
* NOTE: This is not valid to call on a config server instance.
*/
repl::OpTime configOpTime() const;
/**
* Called whenever a mongos or shard gets a response from a config server or shard and updates
* what we've seen as the last config server optime.
* NOTE: This is not valid to call on a config server instance.
*/
void advanceConfigOpTime(repl::OpTime opTime);
/**
* Clears the grid object so that it can be reused between test executions. This will not
* be necessary if grid is hanging off the global ServiceContext and each test gets its
* own service context.
*
* Note: shardRegistry()->shutdown() must be called before this method is called.
*
* NOTE: Do not use this outside of unit-tests.
*/
void clearForUnitTests();
private:
std::unique_ptr _catalogClient;
std::unique_ptr _catalogManager;
std::unique_ptr _catalogCache;
std::unique_ptr _shardRegistry;
std::unique_ptr _cursorManager;
std::unique_ptr _balancerConfig;
// Executor pool for scheduling work and remote commands to shards and config servers. Each
// contained executor has a connection hook set on it for sending/receiving sharding metadata.
std::unique_ptr _executorPool;
// Network interface being used by the fixed executor in _executorPool. Used for asking
// questions about the network configuration, such as getting the current server's hostname.
executor::NetworkInterface* _network{nullptr};
// Protects _configOpTime.
mutable stdx::mutex _mutex;
// Last known highest opTime from the config server that should be used when doing reads.
// This value is updated any time a shard or mongos talks to a config server or a shard.
repl::OpTime _configOpTime;
// Deprecated. This is only used on mongos, and once addShard is solely handled by the configs,
// it can be deleted.
// Can 'localhost' be used in shard addresses?
bool _allowLocalShard{true};
};
// Reference to the global Grid instance. Do not use in new code. Use one of the Grid::get methods
// instead.
extern Grid grid;
} // namespace mongo